According to Poole and Penny, there has been far too much speculation about the origin of eukaryotes. "The conflicting hypotheses currently on offer show a curious disregard for mechanism." Up until the mid-1990s, the 'archezoa hypothesis' was dominant. "This maintained that a protoeukaryote (with nucleus) engulfed the mitochondrial ancestor". Support for the theory came from archezoa: anaerobic eukaryotes with no mitochondria, suggesting that "eukaryotes began diversifying before mitochondria entered the picture". The authors point out that this hypothesis has two independent components: "(a) that a protoeukaryote host (PEH) engulfed the mitochondrial ancestor, and (b) that modern archezoa are 'missing links' that never possessed mitochondria."
Hypothesis (b) "is now universally rejected" and the evidence is that the archezoa are derived, not missing links. The authors continue: "Hypothesis (a) was also rejected, and because eukaryotes and archaea share a number of similar genes, the deposed PEH was replaced with archaea. Consequently, incorporation of the mitochondrion - not the origin of the nucleus - was hailed as the defining event in eukaryotic origins. This opened the floodgates of speculation, and numerous new hypotheses emerged. None is supoported by observation: no archaea reside within bacteria, viruses have preposterously few similarities to the nucleus, and no RNA cells exist." The authors go on to develop their critique of these newer hypotheses and to defend the PEH theory. They argue that a nucleus-bearing protoeukaryote was the direct ancestor of modern eukaryotes.
The comments about "floodgates of speculation" in the name of science are undoubtedly correct. They apply generally to the Darwinian story-telling tradition, in which scientists propose speculative scenarios rather than document the real problems that should constrain thinking. Poole and Penny have provided us with a welcome caution about the way science should be done, but have they really gone further than acknowledging the problems? Their ancestral host is a protoeukaryote, not something else! This is the problem of irreducible complexity (noted previously here and here) and it is not going to go away!
Engulfed by speculation
Anthony Poole & David Penny
Nature 447, 913 (21 June 2007) | doi:10.1038/447913a
Abstract: The notion that eukaryotes evolved via a merger of cells from the other two domains - archaea and bacteria - overlooks known processes.
| Mon | Tue | Wed | Thu | Fri | Sat | Sun |
|---|---|---|---|---|---|---|
| << < | > >> | |||||
| 1 | 2 | 3 | 4 | 5 | 6 | 7 |
| 8 | 9 | 10 | 11 | 12 | 13 | 14 |
| 15 | 16 | 17 | 18 | 19 | 20 | 21 |
| 22 | 23 | 24 | 25 | 26 | 27 | 28 |
| 29 | 30 | 31 | ||||
Evolution has become a favorite topic of the news media recently, but for some reason, they never seem to get the story straight. The staff at Discovery Institute's Center for Science and Culture started this Blog to set the record straight and make sure you knew "the rest of the story".
A blogger from New England offers his intelligent reasoning.
We are a group of individuals, coming from diverse backgrounds and not speaking for any organization, who have found common ground around teleological concepts, including intelligent design. We think these concepts have real potential to generate insights about our reality that are being drowned out by political advocacy from both sides. We hope this blog will provide a small voice that helps rectify this situation.
Website dedicated to comparing scenes from the "Inherit the Wind" movie with factual information from actual Scopes Trial. View 37 clips from the movie and decide for yourself if this movie is more fact or fiction.
Don Cicchetti blogs on: Culture, Music, Faith, Intelligent Design, Guitar, Audio
Australian biologist Stephen E. Jones maintains one of the best origins "quote" databases around. He is meticulous about accuracy and working from original sources.
Most guys going through midlife crisis buy a convertible. Austrialian Stephen E. Jones went back to college to get a biology degree and is now a proponent of ID and common ancestry.
Complete zipped downloadable pdf copy of David Stove's devastating, and yet hard-to-find, critique of neo-Darwinism entitled "Darwinian Fairytales"
Intelligent Design The Future is a multiple contributor weblog whose participants include the nation's leading design scientists and theorists: biochemist Michael Behe, mathematician William Dembski, astronomer Guillermo Gonzalez, philosophers of science Stephen Meyer, and Jay Richards, philosopher of biology Paul Nelson, molecular biologist Jonathan Wells, and science writer Jonathan Witt. Posts will focus primarily on the intellectual issues at stake in the debate over intelligent design, rather than its implications for education or public policy.
A Philosopher's Journey: Political and cultural reflections of John Mark N. Reynolds. Dr. Reynolds is Director of the Torrey Honors Institute at
Biola University.